Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was able to balance a high density neodymium magnet in midair. He pulled off this tricky project using a set of four coils he got off of Taobao (the Chinese version of eBay), a hall effect sensor, and a handful of current regulation ICs.
The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is straightforward. It appears he uses a potentiometer for a rough regulation of the current going to the coils, doing the fine tuning in the code which can be found here (.RAR direct download).
We’ve seen magnetic levitation here before, and this project adds to the list of successful techniques to accomplish this difficult project.